package com.qipay.core.qrcode;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Hashtable;

public class QRCodeUtils {

    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    private static final String CHARSET = "UTF-8";

    private static final String FORMAT_NAME = "JPG";

    // LOGO宽度
    private static final int WIDTH = 60;

    // LOGO高度
    private static final int HEIGHT = 60;

    private QRCodeUtils() {
    }
    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }

    private static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }

    private static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, stream)) {
            throw new IOException("Could not write an image of format " + format);
        }
    }

    /**
     * 生成QRCode的图片到OutputStream中
     * @param content 二维码内容
     * @param width 宽度
     * @param height 高度
     * @param format 输出格式
     * @param stream 输出流
    */
    public static void createQRCodeImageStream(
            String content,
            int width,
            int height,
            String format,
            OutputStream stream
    ) throws WriterException, IOException {
        Hashtable<EncodeHintType, String> hints = new Hashtable<>();
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        BitMatrix bitMatrix=new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        writeToStream(bitMatrix,format,stream);
    }

    /**
     * 生成QRCode的图片到OutputStream中
     * @param content 二维码内容
     * @param stream 输出流
     */
    public static void createQRCodeImageStream(
            String content,
            OutputStream stream
    ) throws WriterException, IOException {
        Hashtable<EncodeHintType, String> hints = new Hashtable<>();
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        BitMatrix bitMatrix=new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, hints);
        writeToStream(bitMatrix,FORMAT_NAME,stream);
    }
}
